1. Field of the Invention
The present invention relates to a prosthetic device, and more particularly to a writing prosthesis useful to provide a means of communication for individuals suffering paralysis of the arm and hand.
It is known that even in mild aphasics, left-sided agraphia is not unusual; what is unusual is the occasional non-hemiplegic aphasic with left-sided agraphia and a moderate preservation of writing ability on the right side.
Some years ago, Leichner demonstrated hemiplegic writing in global aphasia. Using a plastic ball and pen holder in the rigid right hand, the patient made thrusting movements in the forward and backward directions, the hand being repositioned by the examiner for each succeeding stroke.
In 1983 Brown et al. conducted a study of manual asymmetries in graphic and motor performance in aphasics and designed an apparatus which could be moved easily in all directions. The arm was strapped to the device and it was found that the arm and the device could be moved en bloc by the residual proximal minsuclature without assistance from the examiner. This study has demonstrated that severe aphasics, otherwise unable to communicate in speech or with the left hand, may be able to write with the hemiplegic limb with the aid of a prosthesis. As far as we are aware, this demonstration represents a new approach to treatment in aphasia. Thus, not only may severe aphasics retain the ability to write with the hemiplegic limb, but there is seen the possibility that preliminary, subconsious or pre-processing stages in language can be tapped as a means of facilitating communication in aphasia.
2. Description of the Prior Art
There are several previously known devices for assisting in the writing function to facilitate the same or to improve penmanship. Thus, for example, U.S. Pat. No. 2,748,474 is directed to a scribing device having a hand grip mounted on a base which supports a lens and a guard member formed of tinted plastic to minimize eye strain as the operator moves the device on three anti-friction bearings to scribe a surface by shifting a stylus fixed to the device.
U.S. Pat. No. 478,787 discloses a support for writing instruments which comprises a sleeve for holding the instrument and to which is attached a wire formed with a coil or ring to engage the end of a finger of the user. A cup is attached to the coil for containing a ball adapted to contact the writing surface to reduce friction as writing is effected.
A hand splint for use by persons suffering paralysis of the hand is disclosed in U.S. Pat. No. 3,526,006. A person in need of this device can raise his hand at the wrist but cannot press down and the arrangement is such that the force of a resilient member can be overcome by the user's wrist action to open opposed jaws of the device while the resilient force is relied upon for grasping action.
Other patents of interest are U.S. Pat. Nos. 1,197,289, 1,336,432 for writing aids, U.S. Pat. No. 338,239 for a hand suport for use when writing U.S. Pat. No. 2,755,772 for a device for attaching to the arm a writing instrument container including retracting means for the instrument, and U.S. Pat. No. 2,785,462 for a head supported scribing instrument. None of the aforementioned patents offer a solution of the problem discussed above and which we have attacked and solved.